Parchmentized paper



July 9, 1940. R. A. HAYWARD PARCHMENTIZED PAPER Filed Aug. 25, 193'? m mO T T A INVENTOR. /Fafm 02E-.mao

.NI NNW Patented July 9, 1940 ,UNITED STATES PAPER Ralph A. HaywaParchment, Mich., assignor to Kalamazoo .Vegetable Parchment Company,

Parchment, Mich.

Application August z5, issa'serial No. 160,133

2 Claims.

This invention relates to improvements in parchmentized paper.

'I'his invention relates to an improved paper and method of making thesame, and particu- 5 larly parchmentized paper` designed for wrappingproducts and for other purposes where substantial strength isdesirable.,

The main objects of this invention are:

First, to provide an improved parchmentized paper having substantiallyincreased bursting strength, both wet Vand dry, as compared to standardparchmentized paper of similar stock and weight.

Second, to provide an impr'ved method o! manufacturing myimproved'paper.

Objects relating to details` and economies of the invention will appearfrom the description to follow. The invention is deiined and pointed outin the claims.

In the accompanying drawing Fig. 1 is a conventional illustration ofparts of an apparatus by which my improved product may be produced, theparchmentizing apparatus other than the washing notbeing indicated.

Fig. 2 is a plan view of a web of paper illus- .trating the varioussteps of my method'.

In considering the drawing, it will be appreciated that no attempt hasbeen made toshow the parts in proportion and that it is not practical toillustrate with great accuracy the creped material or the nishedproduct.

In the shipping and merchandising of various products, parchmentizedpaper is desirable as, for example, in the crating and shipping oflettuce which is crated wet and frequently with ice enclosed. Also, inpacking, the paper is placed in the press with the lettuce with ice andthe press actuated to compress the contents into the crate dimensionsand this places asevere strain on the paper. Therefore, it is desirableto increase the strength of the paper for this and various other uses.The bursting strength of my paper is very greatly increased over that ofpaper of similar grades produced by other methods, both as to dry testsand greater increases are found on wet tests, that is, as compared withsimilar paper produced by other methods.

In the accompanying drawing I represents a web of paper to be treatedand 2 the washing apparatus for washing the web of paper after it hasbeen subjected to a parchmentizing solution. The apparatus foraccomplishing that step is not illustrated as it is well known in theart:

While the paper is wet and preferably while it is still wet from thewashing step as illustrated in Fig. l, it is passed to a crepingapparatus shown conventionally at l from which which the creped paper ispassed to a drying apparatus. I This drying apparatus and particularlythe support of the paper during the drying step is of primary 5importance. When parchment paper is dried by ordinary methods it shrinksvery substantially, at least ten inches in a hundred inch width of web.By the usual method of drying parchment `paper the paper is held againstthe nat surface 10 of the drier and instead of the paper shrinking tothis i'ull extent there is a tendency for strains to be set up in thepaper-which reduces the ultimate strength of the sheet.

By my method of vthis application the 'parch-4 15 mentized sheetor webis creped and the creped web is fed to the driers so that it reachesthem with the crinkles resulting from the creping still retainedtherein. The paper is so supported during this drying operation that asthe paper zo shrinks the shrinkage is absorbed by the puckers and issuesfrom the driers with the crinkles of the creping step substantiallyeliminated. As there has been no strain developed during the drying, thestrength of the paper is greatly in- 25 creased infact, commonly as mucha's 25% above that of parchmentized paper produced by ordinary methods.

In Fig. 1 of the drawing I illustrate two sections of the driers, thatdesignated by the nu- 30 meral 4 being provided with the paper felt 5and that designated by the numeral 8 being provided with a papercarrying felt 1. The crinkled paper indicated at 8 is delivered from thecreping rolls to the drier unit 4 which is driven ata certain 35 speed,the speed being controllable by a suitable variable speed drive shownconventionally at 9. The second unit 6 is provided with a variable speedcontrol drive shown conventionally at I0.

The paper is passed from the creping machine 40 directly to the unit 4which has its individual felt 5. It is passed from the unit 4 to theunit 8 which has its individual felt 1. The unit 4 does not suicientlyheat or dry the paper to result in i any substantial shrinkage but as itpasses to the '45 unit 6 the-paper is subjected to a complete dryingwhich results in shrinkage. However, in view t of the paper having beenpreviously creped and being fed through the driers without substantialDull or tension thereon, the shrinkage is com- 50 pensated for or takenup by the crinkles of the creping step, with the result that by suitablycontrolling the relativev speeds and supporting the paper during thedrying the crinkles of the creping step are substantially eliminated,andthis without subjecting the bers to stresses which tend to weaken thesheet or web. I1 desired the dried sheet may be subjected to a calenderstack as indicated at Il from which it is passed to the winding roll l2.

In Fig. 2 I show a web of paper illustrating the various steps performedthereon, the acid bath step being indicated at, I3, the washing at I4,the crinkling at l5 and the dryingat |6. I have attempted toy illustrateat I6 the gradual elimination of the crinkles by the drying step. 'I'hei'ln' ished paper indicated at I1 is substantially without crinklesresulting from the creping step, although it will be understood that themethod may be carried out to such degree asdesired.`v

My parchmentized paper has much greater strength, both wet and dryltests, than paper of`v the same weight and stock manufactured by corn-4monly practiced methods of making parchment-.lf

ized paper or any method with which I am familyiar. This increasedstrength, vparticularly 4the bursting strength, iseas'ily 'demonstratedunder Mullen tests, vboth dry tests and wet tests.

While I prefer to' use kraft paper, any suitable grade I of bleached or1unbleached or partially bleached stock suitable for parchmentizing maybe used. The paper may be: manufactured and parchmentized in the usualWay, or any preferred way, and is then subjected to the steps whichresult in the advantage of greatly increased strength as I have setforth.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:

1. The method of making substantially smooth parchmentized kraft papercomprising the steps of subjecting a formed sheet or webof kraft paperto a parchmentizing solution, washing, creping the paper while wet, anddrying while supported so as to permit shrinkage thereof and theabsorption of the shrinkage by the crinkles produced by the creping stepand their substantial kelimination by such shrinkage.

2. The methodl of producing a substantially smooth parchmentized papercomprising subjecting a form, sheet or web of paper to the steps ofparchmentizing, creping, and drying while supported so as to permitshrinkage thereof and the absorption of the shrinkage by the crinklespro-r i duced by the crepi'ng step and their substantial elimination bysuch shrinkage, the paper having a Mullen test bursting strengthsubstantially higher than parchmentized paper not subjected to suchcrinkle eliminating, drying and shrinking steps.

RALPH A. HAYWARD.

